An engine stand is a tool commonly used to repair large heavy gasoline or diesel engines. It uses a heavy cantilevered support structure to hold the engine in midair so that the mechanic has access to any exposed surface of the engine. They are often referred to as cherry pickers. These can be used to take a motor out of or put a motor into a vehicle, as well as mount it to dissect the motor and fix its internal components, without the uncomfortable positions one may encounter working on it while it is still in the engine bay. Many of the stands rotate to give the mechanic easy access to any point on the engine at any time. This makes the engine building process way smoother.
The engine stand is commonly used in combination with the engine crane to remove or install an engine in a vehicle, break in that engine, and perform repairs.